Chapter 3The Japanese Invasion of the Philippines, the Dutch East Indies, and Southeast Asia

Introduction

For several months prior to the outbreak of hostilities on 7 December 1941 the relations between the United States and Japan had been severely strained and a further deterioration was indicated at any moment. The economic sanctions which the Allies had applied against Japan, with her resultant inability to replenish oil supplies made her condition critical. That Japan planned an attempt to make herself self-sufficient by annexing certain of the rich Southern Areas was indicated by such known activities as extensive overseas expeditionary training; the presence of 100,000 troops in Formosa and Hainan; an agreement with the Vichy government whereby 40,000 Japanese troops were stationed in Indo-China and Japan was permitted to occupy strategic air and naval bases there, including Camranh Bay; reinforcement of the Mandated Islands with submarines, aircraft, and land defenses; improvement of airfields and bases on Formosa, the Paracels, Spratly, Saipan, and the Mandates; and storage of oil reserves at such strategic points as Itu Abo, Lord North, and Tobi Islands.

Because of the relatively small forces available to the Allies in the Far East their strategy in the event of war had necessarily to be defensive, pending receipt of reinforcements, and all plans were based on the probable Japanese courses of action.

Conferences between United States, British, and Dutch staff officers resulted in the solving of some operational difficulties, but no firm agreement was reached as to a Supreme Commander or as to air and surface command during joint operations. The basic war plans provided for deployment of the United States Asiatic Fleet to the south where it was to join with the British and Dutch, while the Australian and New Zealand Navies concentrated in their home waters. In the planned deployment of forces, particularly of air forces, there was a general tendency underestimate the Japanese strength and to discount the possibility of the simultaneous attack over a large area which actually occurred.

At the beginning of the war the primary objectives of the Japanese were to make Japan self-sufficient by occupation of the rich area to the south, and to establish and hold a defense line surrounding the occupied are and the Japanese Mainland. This program, while simple in outline, was highly complex in execution. Designed to seize the initiative, the initial phase involved a surprise blow by the bulk of the Japanese carrier forces to destroy or paralyze the American Fleet in Hawaiian waters and to sever communications with the United States Asiatic Fleet, and simultaneous invasions of the Philippines, the Dutch East Indies, and Southeast Asia.

Japanese Plans

In order to carry out such invasions, the Japanese Army and Navy jointly devised the operation plans in minute detail. Each operation was carefully coordinated with, and dependent upon the success of the other. By use of surprise attacks, spearheaded by air power, the Japanese expected to complete the invasions in a very short time and thus free all forces for defense against counterattack or for offensive action in

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other theaters. The following translation of the Japanese War Plans sets forth the general instructions relative to the commencement of hostilities:

The day of opening of operations will be designated X-day and will be determined by Imperial Command.

On X-day initiate a surprise air attack on the Philippines, assault and land on Malaya using air attack as the situation demands. If weather is bad postpone the Philippine landings but execute the Malaya landings so far as possible. After the Malaya landings and air attacks and after the Pearl Harbor strike is completed, activate attacks on Hongkong. If there is a serious attack on Japanese forces prior to X-day, open operations upon receipt of Imperial Command to do so.

In order to insure surprise and reduce the time enroute during which the invasion forces would be subject to attack, such nearby rendezvous points as Indo-China, the Pescadores Islands, Formosa, Okinawa and Palau were selected as standby areas pending commencement of hostilities. (Appendixes 10 and 11).

The first objective in the attacks on the Philippines was the destruction of the United States Far East Air Force. To provide bases from which the short-ranged Japanese Army aircraft could operate, the initial invasion of Luzon was aimed at Aparri and Batan Island. Four days following the outbreak of hostilities an invasion of Davao and Legaspi was scheduled to be staged from Palau, and ten days later (X+14) landings in Lamon Bay and Lingayen Gulf were scheduled. During the consolidation of the Philippines it was planned to launch successive invasions of Menado, Tarakan, Balikpapan, Banjermasin, Kendari, Makassar, Ambon, Timor and Bali. Simultaneously with the occupation of the Philippines, Malaya and Thailand were to be invaded and Miri and Kuching in British Borneo, valuable because of oil, were also to be occupied.

After capture of Malaya, including Singapore, and the occupation of the Philippines, Borneo, Celebes and Sumatra, it was planned to combine all forces and launch an invasion against Java, the heart of the Dutch Empire. By this time it was expected that the Carrier Striking Force would have completed operations in the Pearl Harbor, Wake and Rabaul areas and it was planned also to employ its overwhelming power to insure quick and complete victory.

Upon completion of these plans the Japanese Army and Navy launched intensive training programs designed to fit each unit for the specific mission assigned therein.

Commencement of Hostilities

War was not long in coming. On 5 November 1941 the Commander in Chief of the Combined Fleet was warned by despatch from Imperial Headquarters that war was feared to be unavoidable, and directed to complete all preparations by the first part of December. On 21 November all forces were ordered to proceed to designated rendezvous points, and on 1 December all forces were notified that the decision to enter into a state of war had been made. On 2 December the date to commence hostilities was designated as 8 December. The complete despatches are set forth in Appendix 14.

Because of a heavy fog which grounded Japanese planes in Formosa on the morning of 8 December, it appeared that the key operation of the Philippine campaign, the destruction of American air power in the Philippines, would fail and furthermore that, warned by the attack on Pearl Harbor, the United Sates heavy bombers would initiate an attack on the invasion forces massed in Formosa and then withdraw and disperse. Radio intelligence available to the Japanese on the morning of 8 December indicated that such an attack was planned and all air raid precautions, including protection against gas, were put into effect at Formosan bases. However the attack did not develop and at 1015 of the same morning the 21st and 23d Air Flotillas (Navy) were able to launch all available aircraft for the planned attack on United States air bases in Luzon. Since the attack was not initiated until shortly before noon the Japanese were greatly surprised to find the United States heavy bombers as well as most of the fighters still on the ground.

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Well briefed, as a result of excellent intelligence obtained by photographic reconnaissance prior to the war, the highly trained Japanese pilots delivered an effective 90-minute assault on aircraft and facilities in the Manila area. By the close of 8 December, half of the heavy bomber force and one third of the fighter strength of the United States Far East Air Force had been destroyed, and of the remaining 17 B-17's, 15 P-35's and 50 P-40's many were heavily damaged. By 10 December all remaining United States Army heavy bombers had been withdrawn to the south. The United States Navy search planes followed on 14 December after also losing half of their strength. The few remaining fighter aircraft were used primarily for aerial reconnaissance leaving the Japanese in complete control of the air over the Philippines. Thus the initial phase of the Japanese offensive was a success and their amphibious forces were free to advance virtually unopposed in the air.

Occupation of the Philippines

Following the Luzon air attack, Aparri, Vigan, and the Lingayen area were quickly occupied by the forces of the Third Fleet from Formosa while the Southern Philippine Support Force, operating from Palau with carrier-based air support, occupied Legaspi, Lamon Bay, Davao and Jolo. As the advance into the Philippines progressed, the 5th Air Army moved from Formosa into Luzon where it supported ground operations. The 21st and 23d Air Flotillas (Navy) moved to Davao, Palau and Jolo to cooperate with the 3d Fleet as it moved southward. By the end of December 1941, all large-scale amphibious operations in the Philippines were completed, and the Third Fleet, after refueling at Formosa, proceeded to the Davao-Palau area where forces were assembled for the move on Dutch Borneo, the Celebes, Ambon and Timor. The 5th Air Army was later moved from Luzon to China and all subsequent Japanese Air operations in the Netherlands East Indies theater were conducted by Navy carrier and land-based aircraft.

Malaya Operations

Simultaneously with the Philippine Operations the Japanese successfully advanced into British Borneo and Malaya. Preceded by intensive air attacks by Army and Navy aircraft based in Indo-China and supported by an overwhelming naval force, the landings proceeded on schedule. The highlight of the air action occurred on 10 December when the 22d Air Flotilla, acting upon information furnished by submarines, sank HMS Prince of Wales and HMS Repulse with the loss of only four planes. This action not only removed the only threat to the Malaya invasion forces but also had a tremendous morale effect on all forces involved. Following closely after the air success of Pearl harbor this action again demonstrated the skill of the Japanese pilots and further emphasized the importance of air power as a weapon in naval warfare.

The Organization of the Allied Command

The outbreak of hostilities on 8 December found the majority of the ships of the United States Asiatic Fleet disposed to the south in accordance with previous plans. The submarines and patrol aircraft with their tenders were dispersed through the Philippines. However the immediate destruction of the United States Army's air strength which gave the Japanese complete control of the air made the Philippines untenable even for the submarines. On 14 December what remained of Patrol Wing 10 was ordered south and on 31 December the last of the United States submarines departed from Manila leaving only a few gunboats and motor torpedo boats to continue the struggle along with the ground forces on Bataan and Corregidor.

The southward withdrawal of the United States Asiatic Fleet necessitated a complete reorganization of base and communication facilities. Operational headquarters were reestablished in Surabaya in order to be as near as possible to the scene of operations.

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Meanwhile the situation in Malaya grew progressively worse and the British Far Eastern Command was forced to leave Singapore for Colombo. In order to coordinate the various American, British, Dutch, and Australian forces operating against the Japanese, the Allies, on 2 January, announced the establishment of a unified command (short title--Abdacom) with General Sir Archibald P. Wavell as Supreme Commander. Faced by a rapidly advancing enemy and hindered by almost unsurmountable language difficulties and differences in national attitudes, the command was never more than a paper organization and actually never functioned as a unified command. In fact each nation retained control of its own forces and employed them in its own interests. The British were primarily concerned with convoying troops for the defense of Malaya, and the Dutch also used cruisers and destroyers for convoying merchant ships. This practice prevented full use of the combat ships for strikes against Japanese amphibious forces which advanced through the Celebes rapidly and at small cost.

The Japanese Occupy Celebes and Borneo

In order to execute a simultaneous move through the Molucca Sea and the Macassar Straits, the ships and aircraft assigned to the Japanese Third Fleet were organized as the Netherlands East Indies Force and divided into an Eastern and Western Invasion Force, supported by the 21st and 23d Air Flotillas respectively. The tactics employed by the Japanese were ideal for the conditions encountered. In rapid succession they built up the strength and provided air facilities at one base, overcame weak air opposition at the next point of attack and then, using amphibious forces strongly supported by cruisers and destroyers, easily landed and immediately commenced preparations for the next advance.

Employing paratroops known as the Special Naval Landing Force, the Japanese commenced the Celebes operations by assaulting Menado 11 January and on the same day they also occupied Tarakan on the east coast of Borneo. Balikpapan, Kendari, Macassar, Ambon, Koepang, and Bali were taken in that order, and by the end of February all forces were concentrated for the final push into Java. The movement of Japanese amphibious forces is shown in Appendix 10.

As in the Philippines, Japanese air power was again decisive here. Not only did it make Darwin and Surabaya untenable, but it continually menaced Allied surface forces. In addition the Japanese superiority in the air gave them excellent intelligence of Allied movements and at the same time hindered Allied search operations, largely conducted by the PBY's of Patrol Wing 10.

The opposition to Japanese air power was negligible. With most of its air power destroyed in the Philippines, surviving elements of the United States Army Far East Air Force, operating from makeshift bases in the Dutch Islands, was never able to launch heavy bomber strikes of more than eight to ten planes against the Japanese invasion force. In addition the combined fighter strength of the United States, Britain, Netherlands Indies and Australia was dispersed over such a wide area that it was unable to protect bases and ships or engage actively in offensive operations. The mobile Japanese air forces, manned by experienced pilots and equipped with modern well designed planes, were superior in numbers and performance to any opposition they encountered.

Allied Counteroffensive Efforts

As the eastern prong of the Japanese southern offensive moved through the Celebes, the inadequate and rapidly dwindling air, sea, and submarine forces of the Allies attacked at every opportunity but in no case were they successful in inflicting heavy losses or even in delaying the Japanese operations. The major United States offensive effort occurred off Balikpapan on the night of 23-24 January when a division of four United States destroyers succeeded in sinking four large transports participating in the invasion of Balikpapan. In an effort to repeat the Balikpapan success, a larger Untied States and Dutch striking force, composed of four cruisers and two destroyer divisions was organized and ordered again to attack the

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Balikpapan transports at night. However on 3 February they were sighted by land-based planes operating from Kendari and a heavy attack by all available aircraft of the 21st and 23d Air Flotillas resulted the next day. The Marblehead was permanently disabled, the Houston suffered major damage, and the Dutch cruiser De Ruyter was temporarily damaged, making it necessary to cancel the operation.

The Java Campaign

By 15 February the Japanese were closing in on Java from both the east and west sides with overwhelming strength. In the east, the Japanese controlled all of the Celebes from their strong air base at Kendari, Ambon had been captured, and bombing attacks on Keopang and Bali indicated that these points were scheduled for occupation in the near future.

The invasion of Bali actually occurred on 18 February when the Japanese landed on the southeast coast and seized the airfield, thus exposing the sea area south of Java to air attack. The Allied reaction was immediate but ineffective. On the night of 19-20 February a combined striking force composed of three cruisers and six destroyers attacked a Japanese force of six destroyers and several transports. In a series of short engagements with torpedoes and shellfire, one Allied destroyer was sunk and two cruisers and one destroyer were damaged. The smaller Japanese force lost no ships although one destroyer was moderately damaged and one was so heavily damaged that it had to be towed to Macassar. This marked the first occasion during the campaign in which a Japanese combat ship was damaged to such an extent that it was unable to proceed under its own power. After the engagement the Allied force retired to Surabaya and the Japanese completed the occupation of Bali without major resistance.

On 19 February the Japanese Carrier Striking Force, operating from Staring Bay in Celebes and employing aircraft from four carriers, launched a heavy air attack against shipping and shore facilities at Darwin, Australia. Encountering practically no opposition this strike succeeded in destroying virtually every ship in Darwin in addition to inflicting such severe damage to the airfield and shore installations that immediate evacuation of the town was ordered. The few remaining land-based Australian and American fighters were destroyed, and the reconnaissance seaplanes with their tender were forced to withdraw to the south. On 20 February the Japanese Navy, employing paratroops for the second time, occupied the airfield at Koepang on Timor. Not only did Koepang provide a base from which strikes could be launched against Australia but its occupation also placed the Japanese squarely across the fighter ferry route from Australia to Java.

In the west the danger to Java was equally grave. On 14 February the Japanese Army initiated a surprise paratroop attack on Palembang in southeast Sumatra. Following the initial attack by paratroopers, amphibious forces were landed in large numbers and the fate of Sumatra, which produced half of the oil of the Indies, was sealed. On 15 February, Singapore, the British bastion of defense in the Far East, surrendered unconditionally.

The virtual exhaustion of Allied fighter strength under constant attacks by Japanese aircraft and the Japanese advance to the eastern and western approaches to the Java Sea convinced General Wavell that further defense of Java was useless. Consequently the unified command was dissolved on 25 February, and the Dutch assumed control of the defense of Java. American, British, and Australian Naval forces remained to fight as long as resistance served a useful purpose.

As it was evident that the defense of Java could not be attempted without fighter plane reinforcements, an effort was made to bring in assembled fighters via ship from Australia. After considerable delay due to indecisions incident to the change in high command, the Langley was ordered to sail for Tjilatjap with a cargo of P-40 fighters. During this delay the Japanese had established routine air patrols in the sea area south of Java and the Langley was promptly located and sunk by land-based aircraft from Kendari.

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Battle of the Java Sea

By the end of February the Japanese were prepared for the final two pronged pincer movement against Java. Bali reinforced and at the same time a large convoy moved down from Jolo to the area west of Makassar where it was joined and supported by the forces of the Third Fleet previously engaged in the Celebes operations. Simultaneously a second convoy, supported by the cruisers and destroyers assigned to the Malay Force, approached Banten Bay near the west tip of Java.

To oppose this final thrust by the Japanese there remained a striking force of 2 heavy cruisers, 3 light cruisers and 10 destroyers belonging to four different nations and manned by personnel exhausted by constant activity. Never had this force operated as a tactical unit and there was no common set of signals or communication plan. Under such conditions, the Allied striking force supported by only a token air force was doomed to defeat. In the battle of the Java Sea, 27-28 February, the Japanese, while losing no ships, sank two Allied cruisers and three destroyers and ended all threat to their invasion convoys by splitting the remaining Allied force. The latter ships had no alternative but to attempt escape from the Java Sea through the Japanese controlled exits. In this endeavor the three remaining Allied cruisers as well as four destroyers were lost. The escape of the remnants of the Allied Navy from Java waters on 1 March 1942 marked the end of organized resistance to the Japanese occupation of the Southern Resources Area.

Employment of Japanese Carriers and Battleships

An important feature of the Philippine and Indies-Malaya Campaign was the Japanese employment of battleships, cruisers and large carriers as support forces. Although these ships did not take part in the amphibious operations and indeed participated in only minor surface action, they were always lying off ready to render assistance if necessary. The movements of the Main Body of the Second Fleet together with that of the Carrier Striking Force are shown in Appendix 11. That these ships could participate in such widespread operations perfectly coordinated with the activities of the invasion forces is only another indication of the careful planning and preparation made by the Japanese prior to the war. At the commencement of hostilities, the Main Body of the Second Fleet, which contained the only two battleships during the Southern Operations, moved south towards Singapore to intercept the Prince of Wales and Repulse should the 22d Air Flotilla fail in its attack. From Camranh Bay it moved from operation to operation: after supporting the Lingayen invasion, it proceeded to Palau where it rendezvoused with the Pearl Harbor Striking Force and moved south to the Kendari area to support the Netherlands East Indies Campaign. Except for the carrier attacks on Ambon on 23 January and on Darwin 19 February, this powerful force of four battleships, six large aircraft carriers and several cruisers and destroyers took part in no further action until it arrived in the Indian Ocean on 25 February 1942. Here it operated in support of the Java and Christmas Island invasions and intercepted Allied ships attempting to escape from the Java Sea. Upon completion of the Java operations the force returned to Staring Bay, Celebes, where it refueled and reorganized for the strikes on Colombo and Trincomalee carried out on 5 and 9 April. These strikes were successful and on 18 April 1942, the day of the B-25 raid on Tokyo, the Striking Force arrived back in home waters. Thus, between 7 December 1941 and 9 April 1942, the Japanese Carrier Striking Force operated across 120° of longitude from Hawaii to Ceylon and conducted strikes against ships and shore installations at Pearl Harbor, Rabaul, Ambon, Darwin, Tjilatjap, Colombo, and Trincomalee. Allied losses to Japanese carrier air attack included five battleships, one aircraft tender, one cruiser and seven destroyers sunk or very heavily damaged; three battleships, three cruisers and one destroyer damaged; and thousands of tons of auxiliaries and merchant ships sunk. In addition, hundreds of Allied aircraft as well as docks, hangars and base facilities were destroyed. Despite the scope of the operations not one ship of the Japanese Carrier Striking Force was sunk or damaged by Allied action. Indeed the force was seldom sighted and never effectively attacked.

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Conclusion

The campaign once again demonstrated the military advantage of the initiative and mobility. Utilizing surprise attacks made according to a well conceived plan the Japanese succeeded in bringing superior forces to bear on every objective. By contrast, the Allies were forced to withdraw from one base to another and to reorganize and reestablish communication after every move. This, coupled with the initial lack of coordination between the Allies, prevented a firm and unified stand at any time. The Japanese demonstrated to the world the mobility, range, and striking power of the carrier striking force, and in so doing set the pattern for the Pacific war. But, as in other phases of military operations, the overwhelming initial successes of the Japanese offense blinded them to the necessity of solving the defensive problem of a carrier force faced with serious opposition. The United States solved this problem by improvements in design which reduced the vulnerability of carriers and by the development of radar and specialized tactics which permitted fuller realization of the potentialities of carriers throughout the subsequent course of the war.

The effective employment by the Japanese of amphibious forces and the coordination of air and surface elements including submarines was also indicative of that which was to follow and served notice to the world that in Japan the Allies had a progressive as well as an aggressive foe, well equipped and trained to exploit her initial advantage in military strength.

The Japanese occupation of the Philippines, the Dutch Indies and British Malaya, rich in oil and other essential materials was completed in an incredibly short time. Never before in military history was so much gained in exchange for so little. With the exception of three destroyers, sunk by Allied submarines, not one Japanese major combat vessel was lost and very few were damaged. Air, ground, and shipping losses were equally insignificant, while the United States, Great Britain, the Netherlands, and Australia lost the majority of the sea, land and air forces engaged. April 1942 found the Japanese with their Empire greatly enlarged, their fleet completely intact and the morale of both the military and home fronts sky-high as a result of continuous victory.

But the Japanese could not stand prosperity. Impressed by the apparent weakness of the United States and its Allies and with an inflated estimate of her own offensive power, Japan planned to employ her new found strength for expansion to the eastward. It was this expansion which spread the Japanese force too thin and introduced problems unsolvable with Japan's limited economic and military strength.

Commencing with the Battle of the Coral Sea, a consequence of the first phase of this plan of expansion, Japan suffered a series of irreplaceable losses; she had committed herself to a course of action which served only to hasten her total destruction.

To seize the initiative with a sudden attack on the Philippines and Malaya, while opening operations at the same time elsewhere; and to complete the operations within a short period.

Opening of operations: A sudden assault and landing by the Malaya Advance Force (Senken Heidan) preceded by an air strike. Also an initial air strike on Philippines.

Utilization of the results obtained in the air. Occupation of Malaya and the Philippines by the major portion of the Occupation Forces (Koryaku Heidan).

During the opening period of operations: The occupation of strategic areas in Guam, Honkong, and British Borneo, and the stabilization of Thailand and Indo-China.

During the above operation the occupation of strategic areas in the Bismarcks, Dutch Borneo, and Celebes, as well as in South Sumatra, depending on the progress of the Malaya Operation; and preparations for the Java Operation.

During or after the above the occupation of strategic areas in the Moluccas and Timor.

After neutralization from the air the invasion of Java, and after the occupation of Singapore the occupation of North Sumatra.

If the disposition of the Combined Fleet is shifted to interception because of the movements of the main United States forces, or if war with Russia begins, the Philippines and Malaya Operations will proceed without interruption.

In amphibious operations, anticipate making landings before enemy opposition.

If the British invade South Thailand before us, while we are preparing for operation:

Elements will immediately invade Thailand by land and sea, and will secure Bangkok and an air base to the South. After the Advance Force (Senken Heidan) departed its rendezvous the procedure will be according to schedule. Before departure aerial operations will be accelerated while the landing of the Main Force will be delayed, and then the landing in force will be made. (*Elements of Navy FB (TN: large air unit) will be diverted from the Philippines Area).

If the British or Americans attack us while we prepare for operations:

Local forces will intercept them, an air offensive against the pertinent armies will be opened, and otherwise the predetermined plans will be followed.

The opening of operations.

X-day, the day of the opening of operations, will be determined by Imperial Command.

On X-day we assault and land on Malaya (with an initial air attack depending on the situation) and initiate air attacks on the Philippines. If the weather is bad the Philippines Advance Unit (Senkentai)

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landings will be postponed, but the Malaya assault and landings will be attempted insofar as is possible.

After the Malaya landings and air attacks and after the first strike against the United States has been completed, the attacks on Hongkong and Guam will be activated.

If there is a serious attack by the enemy to seize the initiative before X-day:

We will open our operations after having received an Imperial Command to do so.

We will await such a command until it has been dispatched.

Outline of Operations.

Philippine Operations.

Army and Navy Air Forces will launch the initial air attack from Taiwan and Palau. Naval Forces will maintain Batan Island as an emergency landing field for the attackers.

Various Advance Units.

(X-1) depart rendezvous point; land at Aparri, Vigan, Laoag, Legaspi, and Davao and then occupy Jolo as rapidly as possible. Naval Forces will garrison.

Until about (X+14).

Main force of 14th Army to Lingayen; an element to land on Ramon; occupation of Manila. Cover by force from Third Fleet.

After the main Army forces have been landed: One brigade will mop up Luzon; 48th Division will secure Manila.

Malaya Operations:

25th Army, 3d Air Army, and Expeditionary Fleet will be nucleus force.

Plan A.

Advance Force will assault and land at Ban Don, Nakon, Singora, Patani, and Kota Bharu and will maintain bases.

Army-Navy Air Forces launch the initial air attack from South French Indo-China against enemy air power, ships, and small craft.

Plan B. (If there is difficulty in assaulting and landing.)

The landing of the Advance Force will be an attempt at raids and landings in small numbers. (Launched from the West coast of French Indo-China). The main force of the Advance Force will begin to land after (X+1).

The adoption of Plan B will be determined by Imperial Headquarters before the departure of the Advance Force from its rendezvous point.

After this landing of the Advance Force, it will proceed to land as quickly as conditions permit on Kota Bharu. (Depending on circumstance, the landing may be effected with a small number of troops at the same time as the main force of the Advance Force).

Upon the return of an element of the 14th Army's escort shipping, the main force of the 25th Army will land at Singapore from South Thailand and then, if the opportunity presents itself, will endeavor to debark one group (Heidan) on the East coast of South Malaya.

British Borneo Operations.

First, a sudden attack will be launched on Miri by an element directly attached to the Southern Army and then Kuching will be occupied; bases will be maintained; Navy Air Force will support the operation.

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Hongkong Operations.

One Group of 23d Army, and 2d China Fleet as nuclear force.

Annihilate local enemy shipping, assault enemy positions on the Kowloon Peninsula, occupy Hongkong. After completion of the occupation, the group above will be assembled as the group to occupy the Netherlands East Indies.

The Guam and Bismarck Operations nuclear force of South Seas Detachment and 4th Fleet will seize Guam; land combat unit to relieve as garrison. To occupy Rabaul; land combat unit to relieve as garrison.

Netherlands East Indies Operations.

To occupy Batavia, Bandoeng, Surabaya:

Main Force of 16th Army in vicinity of Batavia; one group diverted to vicinity of Surabaya.

Element of 16th Army to Tarakan, Balikpapan, Bandjoermasin, Ambon, Koepang. (Navy to relieve Tarakan and Abmon as garrison.)

Navy to Manado, Makassar.

Element of 16th Army to strategic areas of Bangka Island, and Palembang.

Elements of 25th Army to land on Madang from West Coast of Malaya, and occupy Achie and then Sabang.

Thailand and Burma Operations.

Element of 15th Army (main strength assigned from 25th Army) to South French Indo-China, South Thailand, Victoria Point.

The main force of the 15th Army to the vicinity of Bangkok, one group by land route from French Indo-China, one group from North China abut (X+40). Depending on the arrival of the main force of the 15th Army, an element of the 25th Army will advance to the main force's area.

An element of the 15th Army to occupy Moulmein Base.

Command.

Army-Navy cooperation.

In local land operations there will be a consolidated command, depending on circumstances.

Imperial Navy's Course of Action in Operations Against United States, Great Britain, and the Netherlands
Formulated in November, 1941 (Translation)

Outline of Operations.

Continue control over China Coast and Yangtze River.
Quickly destroy enemy fleet and air power in East Asia.
Occupy and hold strategic points in Southern Area.
Destroy enemy fleet in Hawaii.
Consolidate strength to hold out for a long time.
Destroy enemy will to fight.

Combined Fleet Course of Action.

General Operations

With the forces in Second Fleet, Third Fleet, Combined Expeditionary Fleet and Eleventh Air Fleet as a nucleus destroy enemy fleet in the Philippines, British Malaya and Netherlands Indies.

Early stages of operations.

First occupy British Borneo and then as quickly as possibly occupy Dutch Borneo, Celebes and Southern Sumatra. The above to be followed by occupation of Molucca Islands and Timor.

Establish air bases in all of the above named places. Utilize air bases for subjugation of Java and then occupy Java. After capture of Singapore, occupy northern Sumatra and then at an opportune time commence operations in Burma. Cut supply routes to China.

Forces of the Fourth Fleet.

Defend the South Seas Islands, patrol, maintain surface communications, capture Wake. At opportune time attack and destroy enemy advanced bases in South Pacific Area. In cooperation with Army capture Guam and then Bismarck Area.

Forces of the Fifth Fleet.

Patrol the area east of the home islands. Make preparations against surprise attacks by enemy. Make reconnaissance of Aleutians and defend Ogasawara. Maintain surface communications. Be on guard against Russia.

Forces of the Sixth Fleet. (Submarines)

Make reconnaissance of American fleet in Hawaii and West Coast areas and by surprise attacks on shipping destroy lines of communications.

Forces of First Air Fleet. (Carriers)

Attack enemy fleet in Hawaii and reduce its strength. Thereafter support 4th Fleet operations and assist in capture of Southern Areas.

Main body of Combined Fleet.

Support operations in general. Operate as suitable.

Part of Combined Fleet.

Destroy enemy lines of communication in the Pacific and Indian Oceans.

Second Phase of Operations.

Forces of sixth Fleet. (Submarines)

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Make reconnaissance and surprise attacks on main forces of enemy fleet. Destroy enemy surface communications in cooperation with a part of Combined Fleet. At opportune time make surprise attacks on enemy advanced bases.

Forces of First and Eleventh Air Fleets. (Carriers and land-based bombers)

Search for and attack enemy forces. Destroy enemy advanced bases.

Forces of Third Fleet, Expeditionary Fleet and other forces as necessary.

Defend and patrol points in South Sea Islands and Bismarcks. Maintain surface communications. Search for and attack enemy shipping. Make surprise attacks and destroy enemy bases on our perimeter.

Forces of Fifth Fleet.

Defend Ogasawara and patrol area to north of those islands and east of home islands. Maintain surface communications. Search for and attack enemy fleet should it appear in the area. Attack and destroy enemy bases in the Aleutians.

Part of Combined Fleet.

Destroy enemy surface communications in Pacific and Indian Oceans.

Main Body of Combined Fleet.

Support all operations. Operate as required.

In case of attack by strong American Force.

Maintain contact with part of Sixth Fleet. Reduce enemy strength by air and submarine attacks. At suitable opportunity assemble major portion of Combined Fleet and destroy enemy.

In case of attack by strong British Force.

By movement of Third Fleet, Fourth Fleet, Expeditionary Fleet, air force, and submarine squadrons maintain contact with enemy force and destroy it by concerted attack. The main body of Combined Fleet, depending upon condition and location of American Fleet, will also be used in destruction of British Fleet.

The important points to be defended among the points which were occupied were as follows: (Asterisk indicates advanced bases).

Continue operations against China. Cooperate with the in destruction of United States and British forces in China. Second China Fleet cooperate with Army in capture of Hongkong and destruction of enemy forces there. Maintain surface communications along China coast. Prevent enemy from using China coast. Cooperate with Combined Fleet and Army in operations. (Escort of surface transport and defense of assembly points).

Japanese Naval Despatches Ordering Commencement of Hostilities

5 November 1941.

From:

The Chief of Naval General Staff

To:

CinC Combined Fleet

In view of the fact that it is feared war has become unavoidable with the United States, Great Britain, and the Netherlands, and for the self preservation and future existence of the Empire, the various preparations for war operations will be completed by the first part of December.

The CinC of the Combined Fleet will effect the required preparations for war operations.

Execution of details will be as directed by Chief of the Naval General Staff.

5 November 1941.

From:

The Chief of Naval General Staff

To:

CinC China Area Fleet

view of the fact that it is feared war has become unavoidable with the United States, Great Britain, and the Netherlands, and for the self preservation and future existence of the Empire, the various preparations for war operations will be completed by the first part of December.

The CinC Combined Fleet will effect the required preparations for war operations in accordance with Imperial Headquarters Order, No. 1.

The CinC of the China Area Fleet will continue operations against China and at the same time effect required preparations for war operations.

Execution of details will be directed by Chief of the Naval General Staff.

7 November 1941.

From:

The Chief of Naval General Staff

To:

CinC Combined Fleet

CinC Combined Fleet, as a measure of self defense, is authorized to carry out operations against Portuguese Timor in cooperation with Commander, Southern Army.

Execution of details will be as directed by Chief of Naval General Staff.

7 November 1941.

From:

CinC Combined Fleet

To:

First Air Fleet

The Task Force, keeping its movement strictly secret, shall assemble in Hitokappu Bay by 22 November for refueling.

NOTE: (Upon arrival at Hitokappu Bay all ships with a limited cruising range were deck loaded with drums of fuel oil and oil was stowed in all available spaces inside the ships.)

21 November 1941.

From:

The Chief of Naval General Staff

To:

CinC Combined Fleet

CinC Combined Fleet will order forces necessary for war operations to proceed to suitable standby areas.

During the period CinC Combined Fleet is preparing for war operations should any challenge be received from United States, British or Dutch forces he is authorized to utilize any strength he may deem necessary for self defense.

Execution of details will be as directed by Chief of Naval General Staff.

--49--

21 November 1941.

From:

The Chief of Naval General Staff

To:

CinC China Area Fleet

During the period CinC China Area Fleet is preparing for war operations should any challenge be received from United States, British or Dutch forces he is authorized to utilize any strength he may deem necessary for self defense.

Execution of details will be as directed by Chief of the Naval General Staff.

25 November 1941.

From:

CinC Combined Fleet

To:

First Air Fleet (Pearl Harbor Attack Force)

The task force, keeping its movement strictly secret and maintaining close guard against submarines and aircraft will advance into Hawaiian waters, and upon the very opening of hostilities shall attack the main force of the United States Fleet in Hawaii and deal it a mortal blow. The first air raid is planned for the dawn of X-day (exact date to be given by later order).

Upon completion of the air raid, the task force, keeping close coordination and guarding against the enemy's counterattack, shall speedily leave the enemy waters and then return to Japan.

Should the negotiations with the United States prove successful, the task force shall hold itself in readiness forthwith to return and reassemble.

25 November 1941.

From:

CinC Combined Fleet

To:

First Air Fleet (Pearl Harbor Attack Force)

The task force keeping its movement strictly secret, shall leave Hitokappu Bay on the morning of 26th November and advance to 42° N. 170° E. on the afternoon of 3 December and speedily complete refueling.

1 December 1941.

From:

The Chief of Naval General Staff

To:

CinC Combined FleetCinC China Area Fleet

It has been decided to enter into a state of war between the Imperial Government on one side and the United States, Great Britain and the Netherlands on the other during the first part of December.

The CinC Combined Fleet will destroy the enemy forces and air strength in the eastern seas at the same time will meet any attack by the enemy fleet and destroy it.

The CinC Combined Fleet will, in cooperation with the Commander of the Southern Army, speedily capture and hold important American and British Bases in Eastern Asia and then Dutch bases. Important strategic points will then be occupied and held.

CinC Combined Fleet will in case of necessity cooperate with the operations on China Area Fleet.

The time for activating the movements of forces in accordance with preceding articles will be given in a later order.

Execution of details will be as directed by Chief of the Naval General Staff.

--50--

1 December 1941.

From:

The Chief of Naval General Staff

To:

CinC Combined Fleet

Japan under the necessity of her self-preservation, has reached a decision to declare on the United States of America, British Empire, and the Netherlands. Time to start action will be announced later. The CinC Combined Fleet shall, at the start of war direct an attack on the enemy fleet in the Hawaiian area and reduce it to impotency using the First Air Fleet as the nucleus of the attack force.

NOTE: (The above despatch was issued by Admiral Nagano under authority delegated by Imperial Order. The commencement of hostilities was decided by Cabinet Council on 1 December).

2 December 1941.

From:

The Chief of Naval General Staff

To:

CinC Combined Fleet

CinC Combined Fleet will activate the force under his command in accordance with Imperial Headquarters Order No. 9 on and after 8 December.

Operations against the Netherlands will be initiated when opportunity offers after operations against the United States and Great Britain have started.

Executing of details will be directed by Chief of the Naval General Staff.

2 December 1941.

From:

The Chief of Naval General Staff

To:

CinC Combined Fleet

The hostile action against the United States of America, the British Empire, and the Netherlands shall be commenced on 8 December. Bear in mind that, should it appear certain the Japanese-American negotiations will reach an amicable settlement prior to the commencement of hostile action, all forces of the Combined Fleet are to be ordered to reassemble and return to their bases.

2 December 1941.

From:

CinC Combined Fleet

To:

Pearl Harbor Task Force (First Air Fleet)

Execute attack X 8 December designated as "X" day.

NOTE--(1) The decision to commence hostilities was made by Cabinet Council on 1 December.
(2) On 2 December Imperial General Headquarters issued the order establishing 8 December 1941 as the date on which hostile action was to begin.